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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/102181] std::advance and std::views::iota<std::int64_t> don't work Date: Thu, 02 Sep 2021 21:59:19 +0000 [thread overview] Message-ID: <bug-102181-4-dO87dgKdOL@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-102181-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102181 --- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- https://en.cppreference.com/w/cpp/iterator/advance says "InputIt must meet the requirements of LegacyInputIterator." https://en.cppreference.com/w/cpp/named_req/InputIterator gives a sample concept you can use to test whether something meets those requirements. The iterator_t<iota_view<int64_t, int64_t>> type does not satisfy that concept. I think GCC is behaving according to the standard. You can use std::ranges::advance because that requires std::input_or_output_iterator, which is satisfied by your iota_view's iterator. #include <ranges> int main() { using type = std::int64_t; // using type = int works! auto v = std::views::iota(static_cast<type>(0), static_cast<type>(100)); auto b = v.begin(); static_assert( ! __LegacyInputIterator<decltype(b)> ); // So this can't work: // std::advance(b, 1); static_assert( std::input_iterator<decltype(b)> ); // So this can work: std::ranges::advance(b, static_cast<type>(1)); }
next prev parent reply other threads:[~2021-09-02 21:59 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-02 20:28 [Bug libstdc++/102181] New: " raffael at casagrande dot ch 2021-09-02 21:36 ` [Bug libstdc++/102181] " redi at gcc dot gnu.org 2021-09-02 21:44 ` redi at gcc dot gnu.org 2021-09-02 21:51 ` raffael at casagrande dot ch 2021-09-02 21:59 ` redi at gcc dot gnu.org [this message] 2021-09-02 22:13 ` redi at gcc dot gnu.org 2021-09-02 23:35 ` redi at gcc dot gnu.org 2021-10-12 15:49 ` cvs-commit at gcc dot gnu.org 2021-10-12 16:11 ` [Bug libstdc++/102181] [DR 3197] " redi at gcc dot gnu.org
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